Water softeners are used to remove calcium and other deposit causing materials from the untreated or “hard water.” The water softener has an ion exchange process taking place in an ion-exchange resin bed stored in a resin tank of the water softener. As the water that is to be processed passes through the resin-filled tank, ions of calcium and other minerals in the water are exchanged with ions found in the resin, e.g., sodium, thereby removing objectionable ions from the water and exchanging them with less objectionable ions from the resin.
The capacity of the resin to exchange ions is finite and is reduced during the ion exchange process. Water softeners are generally operative to periodically regenerate the ion exchange resin stored in the resin tank. Regeneration generally involves chemically replacing the objectionable ions such as calcium ions from the resin with less objectionable ions such as sodium ions. This replacement is typically performed by introducing a regenerant solution of sodium chloride or potassium chloride into the resin bed from a brine tank and thereafter flushing the regenerant solution from the bed. Regeneration of a water softener resin bed may be performed in a direction that is the same as the flow of water to be treated. This is generally known as “downflow regeneration”. Regeneration of a water softener resin may be performed in a direction that is opposite to the flow of water being treated. This is generally known as “upflow regeneration”. The resin bed is backwashed in order to remove trapped particulate matter, and the resin tank can be rinsed to remove objectionable soluble materials. In order to prevent interruption of service, most water softeners are configured to allow a bypass flow of untreated water directly to the service lines during backwash, rinse, and regeneration.
Water softeners may benefit from improvements.